ADFS Saml configuration

If not already done, SAML should be enabled on ADFS. See e.g. docs.servicenow.com/bundle/jakarta-platform-admi.. and docs.servicenow.com/bundle/jakarta-platform-admi..
Next, set up the Viadesk domain as a relying party. You can find a step by step example here: sharepointpals.com/post/Step-by-Step-Procedures-..
Please note that since the June 2018 Viadesk update, we also need to configure the Name ID in ADFS. See steps 9 - 15 here: docs.servicenow.com/bundle/geneva-servicenow-pla..
In Viadesk, the relying party data must be configured, at least:

The adfs saml url, usually something like https://[ADFS DOMAIN]/adfs/ls/idpinitiatedsignon.aspx
Choosing whether to create participants automatically
A mapping from SAML 'claims' to viadesk participant fields
The ADFS metadata, typically at https:///[ADFS DOMAIN]/FederationMetadata/2007-06/FederationMetadata.xml